Sulfonylurea compounds and biguanide compounds are currently used clinically as synthetic hypoglycemic drugs for the treatment of diabetes. Biguanide compounds, however, are rarely used because it induces lactic acidosis and their application is therefore restricted. On the other hand, sulfonylurea compounds show secure hypoglycemic action and hardly generate side effects, but it is necessary to take great caution in using them because they sometimes cause hypoglycemia.
In recent years, insulin sensitivity-increasing drugs capable of showing hypoglycemic action by increasing insulin sensitivity in peripheral tissues have been drawing attention as a successor for the aforementioned synthetic hypoglycemic drugs.
Compounds having the insulin sensitivity-increasing action have been synthesized as disclosed, for example, in International Patent Publication No. 92/03425 pamphlet (1992).
Under such circumstances, the inventors of the present invention have previously found that a bisoxa or thiazolidine derivative has excellent insulin sensitivity-increasing action and have filed a patent application [cf. International Patent Publication No. 93/03021 pamphlet (1993)].